Observations on the airline pilot group probably come as close to a true reflection of incidence of disqualifying disease as is possible to observe. Prescreening by airline companies before employment and the stringent Federal Aviation Administration (FAA) requirements for issuance of a first-class medical certificate result in this group being essentially purged of disease prevalence that contributes to higher rates for other groups. Also, because of occupational/economic reasons, these individuals are less likely to voluntarily remove themselves from followup observation for known medical conditions that would preclude FAA medical certification. Conversely, voluntary attrition is a more frequent occurrence among nonoccupationally connected pilots who recognize that they are not medically qualified and, therefore, are never heard from again by the FAA. Age-specific denial rates for airline pilots increase to the highest rate at age interval 55-59. The most significant causes for denial are cardiovascular, neuropsychiatric, and the miscellaneous category. The importance of these causes for denial, particularly above age 45, is again recognized. Age- cause-specific findings for the airline pilot group follow epidemiologic expectations, with age being a significant variable associated with increased rates. Of interest in the data on denial be employer is that the larger employers, many of which have their own medical facilities, have uniformly lower denial rates than smaller employers.